William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London.
Adult Critical Care Unit, Royal London Hospital, London, UK.
Curr Opin Clin Nutr Metab Care. 2021 Mar 1;24(2):183-188. doi: 10.1097/MCO.0000000000000718.
To review the mechanisms how intermittent feeding regimens could be beneficial in critically ill patients.
Large randomized controlled trials (RCTs) have failed to demonstrate consistent benefit of early, enhanced nutritional support to critically ill patients, and some trials even found potential harm. Although speculative, the absence of a clear benefit could be explained by the continuous mode of feeding in these trials, since intermittent feeding regimens had health-promoting effects in healthy animals and humans through mechanisms that also appear relevant in critical illness. Potential protective mechanisms include avoidance of the muscle-full effect and improved protein synthesis, improved insulin sensitivity, better preservation of circadian rhythm, and fasting-induced stimulation of autophagy and ketogenesis. RCTs comparing continuous versus intermittent feeding regimens in critically ill patients have shown mixed results, albeit with different design and inclusion of relatively few patients. In all studies, the fasting interval was relatively short (4-6 h maximum), which may be insufficient to develop a full fasting response and associated benefits.
These findings open perspectives for the design and clinical validation of intermittent feeding regimens for critically ill patients. The optimal mode and duration of the fasting interval, if any, remain unclear.
探讨间歇喂养方案在危重症患者中的有益作用机制。
大型随机对照试验（RCT）未能证明早期强化营养支持对危重症患者有一致的益处，一些试验甚至发现潜在的危害。尽管推测，这些试验中连续喂养模式可能解释了缺乏明确益处的原因，因为间歇喂养方案在健康动物和人类中具有促进健康的作用，其机制在危重病中似乎也有相关性。潜在的保护机制包括避免肌肉饱食效应和改善蛋白质合成、提高胰岛素敏感性、更好地维持昼夜节律以及禁食诱导的自噬和酮体生成的刺激。比较危重症患者连续与间歇喂养方案的 RCT 结果不一，尽管设计和纳入的患者相对较少。在所有研究中，禁食间隔相对较短（最长 4-6 小时），可能不足以产生完全的禁食反应和相关益处。
这些发现为危重症患者间歇喂养方案的设计和临床验证开辟了新的思路。最佳的禁食间隔模式和时长（如果有的话）仍不清楚。
